Self-regulating dynamo-electric machine.



A H MIDGLEY &C A VANDEBVELL SELF REGULAT ING DYNAMDAELECTRIC MACHINE.

I I APPLICATION FILED OCT. 30. I911. 1,217,482. Patented Feb-27,1917.

UNITED STATES PATENT OFFICE.

ALBERT HENRY MIDGLEY AND CHARLES ANTHONY VANDERVELL, or ACTON VALE,

' ENGLAND.

To all whom it may concern:

Be it known that we, Apn nn'r HENRY Mme LEY and Cimnms Ax'rno Y vlmmawnnn, both subjects of the King of Great Britain and Ireland, and residing at \Varple \Vay, Acton Vale, in the county of Middlesex, England, have invented certain new and useful Improvements in and Relating to Self-Regulating Dyna mo-Electric Machines, of which the following is a specification.

This invention relates to a variable speed dynamo machine of the kind which is selfregulating and supplies a current always flowing in the same direction independently of the direction of rotation of the machine. The machine is therefore especially adxan: tageous for being used for train and car lighting purposes in conpmction with a battery or accumulators.

In the accompanying drawings Figure 1' is a diagrammatic representation of a machine constructed according to the present nvention.

Fig. 2 is a diagrainn-iatlc representation of the path of the magnetic fluxes due-to each magnetizing force separately in the machine shown in Fig. 1, and

Fig. 3 is a diagrammatic representation. of the. paths of the resultant magnetic fluxes in the machine due. to the .tll'lOllS effects produced as shown in Fig. 2.

Referring to Fig. 1, the machine has main poles 6 each of which is provided with a winding a, the two ends connected to a main brush efan-d a supplementary brush 0 respectively, spanning the armature conductors. under each main pole, and supplementary poles 0, each of which is provided with a winding (Z, the ends connected to the mainbrush 6 and supplementary brush span ning the armature conductors under each supplementary poleso that the ends of the winding -on each pole are electrically con-" nected with the ends of the windings on the -.rection that the nppenand right hand'polesp p r p 1 higher value than the'fiux" Z morder to-p'ro-f two adjacent poles: i

The windings a and I are wound in such a manner that, assuming the machine to supply a current in the direction indicated by the arrows, the currents flowing through said windings produce in the poles. on which they are wound magnetic fluxes ofisuch a diwould tend to become north poles, and the lower and left-band poles south poles, re- SPGCtIYGlY. a I I Specification of Letters Ifeten t.

Patented Feb. 27, 191".

Application filed 0ctober30, 1911. Serial No. 657;635.

d. When the machine rotates in a direction opposite to that indicated by the arrow, the right and left-hand poles act as main north and south poles, respectively, while the up.

per and. lower poles act as supplementary poles, their polarity above-referred to being reversed, this being determined by the armature cross-flux due to'the current produced by the poles 0 now acting as main poles. v \Ve have ascertainedlthat in this machine the direction ofthe magnetic ilnX in the portionsof the yoke between the upper and right-hand'pole and between -tl ie'l'ower and left-hand pole is reversed when the rotation o-fthe machine isa-erersed', but that'the cli rcction of themagnctic flux in the portions between the upper and left-hand pole and betwcen'the right-hand and lower pole 'is' alwa the same independently of the direc-' tionot' rotation of the machine, the conse j quence being that the residual magnetism of; the yoke is always such as to cause the upper and right-hand poles to primarily act as north poles, anil'the' lower and 'lei t hiulfl poles as south poles independently of 'the di rcction of rotation of the machine when the same-was last lIl'ODOl'iitlOl];

lly reference to Fig; 2 it will be seen that the flux due to "the \vindings a is" represented by the chain lines ]I- and thcllux due to the conductorsflying under the ordinary poles l) is representedby the cha'in lines" The fluxduc-to the windings I] -isr e .iresentecl'by the chain lines Z; while'the flux'due to 'tlie current; in the armature conductors glunde'rj duce the working current of the machine";

Referr ng' toFig; it w l ljfbe seen' th atihen the 'nmchine'rotates in "the direction .of the field of the armature conductors with the armature rotating in the direction indicated by the arrow, the resultant effect o the various magnetizing forces shown in 1 lg. '2 is to produce a magnetic flux r which passes through the main poles b and through the yoke of the machine anda small auxil-.'

iary flux 8 which passes through the supplementary poles through the main poles b and through the yoke of the machine, the direction of the fluxes being indicated by the arrows.

'hen the armature is rotated in the direction of the arrow, viz; anti-clockwise the operation of the machine 1s as follows Starting with the upper and right hand poles of north polarity, the upper )ole will be strengthened by reason of the act that the current in coil (1- assists the residual magnetism. Regarding poles. b as the main poles, the upper right hand brush 0 will be positive and the lower left hand brush n'eqative. Current will flow from the upper right hand brush (2 through coil 11- to lower right hand brush a, thence throngl-ithe armature" to the upper left hand brush 1; through coil (1 on the left hand pole to the lower left main brush. The residual flux from poles- 0 tends to make lower, right hand brush e ,positive to the upper right hand brush e and tends to send the current through coil (I to weaken this residual flux. This current does not, however, flow but an electromoti've force is produced between brushes 0 and e which weakens the )OlPS'C below the'strength they would have i this electromotive force were not produced. 'hen the speed reaches the predetermined value, poles I) are so strong that full voltage is produced at main brushes 6. The cross flux, due to the main line current, now reverses the residual flux from poles c. This cross flux produces anelectrouiotive force whichnow assists the current flow in coil (l and this coil now tends to weaken the cross finx.-

If the speed of the nnichine'after the same has attained its'normal workingspced is increased the elcctroi'notivc force induced in the conductors f is also increased, the result being that the field of, the armature conductors f is increased. In consequence thereof the potential ditl'eren'ee between the brushes 0 and a spanningthe conductors g is also increased and therefore also the current flowing through the winding (1 in the direction indicated lgy the arrow 18 increased.

. This'current produces a field which acts in opposition to the field of the armature conductors f. the same time theotential difference between thebrushes' e an a spanning the armature conductors. g is increased merely because of the increase of I speed apart from the increase due to the increasfe The field of the winding (1 will therefore increase quicker than the field-ofithe arma;

ture conductors f which acts in opposition thereto so that the resulting apxillary field speed-is increased and the co sequence being that while the 'demagneti ing action of the current flowing through the armatureconductors y, and due to the cross-flux is decreased, the reduction of the auxiliary field s has a preponderating eti'ect so that a constant voltage regulation is o tained.

On slowing down, when tl e main current falls to zero, the cross flux alls to zcrobut current stillflows in coils I because main poles b are still strong and cause a current to How from the main posi ive to the main negative brush through coils (l in series as at the beginning of the cdqmter-elockwise '8 (Fig. 3) is rapidly diminisjicd when the.

rotation. This-current cans s the right hand pole to become a north po e and the lefthand pole to become a south pole, which leaves the upper and right poles of north polarity as required.

As above explained .thei;f nnctions of the poles of this machine are interchanged when the direction of rotation is changed, that is to say, the poles acting asiimain poles when themachine rotates in oneiidirection become the supplementary poles when the machine rotates in the opposite direction, and vice versa, the function of the lirushes remaining the same in both directions'jof rotation.

' The operation of the n'iachine when its direction of rotatioirindicirted by the arrow is reversed is as follows:

The residual flux from poles 0 produces an clectromotive force which produces a cur: rent in windings (I which strengthens poles c, which now become the main poles. A current is produced by poles c which flows from the upper main brush 6 to; the upper-coil a to brush 0' and lower coil a to lowermain brush e. This current is, however, opposed by an electroniotive force produced in the armaturcby the residual magnetism of poles 1), hence the poles b are weak and the poles strong. The main field of the machine is thus reversed from its direction. at cmmter-clockwise rotation and the mam brushes are, therefore. of the same polarity as they were with the opposite rotation. \Vhen the current is taken from the armatune the crossflux reverses the residual flux through the poles, b and the windings a now act to oppose the cross flux to produce the desired re ilation.

The operation of the machine when its speed 18 increased after the machine has attained its normal working speed is similar -to that referred'to in connection with the' operation of the machine when the same rotates in the direction of the arrow, viz; anticlockwise- On slowing down, when the main current falls to zero, the cross flux falls to zero and a weak current, due to poles 0, again flows we claim as new anddesire to secure by Letters Patent is: y

1. A self-regulating variable speed continuous current machine comprising in combina-tion an armature, armature conductors, main and supplementary poles, main and supplementary brushes arranged between the main and supplementary poles and windings on the main and supplementary poles, these windings being cyclically connected together and wound on the main poles in one sense and on the auxiliary oles-in the opposite sense with respect to the main brushes and the main and auxiliary brushes spanning the armature conductors under a main pole being connected to the ends of the winding on a main pole, and the main and auxiliary brushes spanning the armature conductors under a supplementary pole being connected to the ends of the winding on a supplementary pole, as set forth.

2. A. reversible and self-regulating variable speed continuous current machine com- Gopi'el 0! this patent pay obtained for prising in combination an armature, armature conductors, one set of poles, another set of poles, main and supplementary brushes arranged between the main and supplementary poles, windings on the poles belonging to the one set and on those belonging to the wound on the poles belonging to one set in one sense and on the poles belonging to the other set in the opposite sense with respect to the main brushes and the'main auxiliary brushes spanning the armature conductors under a main pole being connected to the ends of the winding on a main pole and the main and auxiliary brushes spanning the armature conductors under a, supplementary pole bei'ngconnected to the ends other set, the windings on all poles being cyclically connected together and being' of the winding on a supplementary pole,

whereby when the machine is rotated in the one direction the poles belonging to one set are excited and' act as the main poles, while the other poles act as auxiliary poles, while the functions of these poles are reversed when the machine is rotated in the opposite direction, as set forth.

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.

AlfBERT HENRY MIDGLEY.

CHARLES ANTHONY VANDERYELL.

Witnesses:

RICHARD A. HOFF ANN, CHARLES J. R. BULLOUGH.

five cents each, by addressing the Commissioner 0! Talents, wummn, no." 

